When Barack Obama made history a year ago by getting elected the first black president of the U.S., he did it in part by changing the electorate. He brought in millions of new voters.

But one year later, Obama and the Democrats were unable to get those "Obama surge" voters back to the polls.

And while there's a feisty argument going on about what the election results mean, there's no argument about the score: The Democrats got a slap in the face. The Republicans got a much-needed victory.

"The bottom line is that the GOP last night became, I think, transcendent in that it moved beyond the past losses and no message and no meaning for the American people," said Republican National Committee Chairman Michael Steele. "And I think yesterday we had candidates who set some milestones for us and now, hopefully, point the way for 2010 and beyond."

Some Republicans went further and claimed that the vote was a referendum on the president and his policies.

But exit polls show that in New Jersey and Virginia, the president wasn't a factor — and he still has high approval ratings in those states.

So why wasn't Obama, with his campaign visits to those states, able to turn out voters who supported him just one year ago?

"Enthusiasm isn't always transferable — and particularly when you're asking people to vote in a state race that is a little bit removed from the national issues and national race," says David Axelrod, Obama's top political adviser. "I think you're going to see a lot of folks who were supportive of the president last year re-engage for national elections next year. And, obviously, we'll work very hard to keep them engaged."

One important lesson from Tuesday's vote, says analyst Charlie Cook, is that the "Obama phenomenon" only works when he himself is on the ballot.

"It was gone last night," Cook says. "President Obama still had positive job approval ratings in both Virginia and in New Jersey, but that wasn't enough. It didn't convey the young people, and minorities didn't show up so much. And the independents didn't swing their way."

A Damaged Republican Brand, A Fired-Up GOP Base

The question for Republicans is whether they can capitalize on this. The Republican base is fired up and ready to go, just like the Democrats were last year.

But the Republican brand is still damaged: Less than 25 percent of voters identify themselves as Republicans, says former Rep. Tom Davis, who used to lead the party's congressional campaign committee.

"The other thing you have to remember — and this is going to apply to the midterms as much as anything else: Voters aren't putting Republicans back in power, they're just putting a check on Obama," he says. "They've already rendered their verdict on Republicans: They don't like them. Any gains the Republicans make aren't because the Republicans have changed. It's just because maybe voters feel maybe the Democrats have gone too far, and they want to send them a message."

Republicans learned other lessons Tuesday evening. In Virginia, Cook says, where Bob McDonnell won the governor's race, they may have found a model for how committed social conservatives can win in swing states.

"They nominated a conservative — a staunch conservative — but one who projected a very moderate, mainstream, nonthreatening image and stylistically [is] a moderate," Cook says.

Going Against The President's Agenda?

For the White House, there's a danger in the way the results could be interpreted, particularly by Democrats in Congress from districts carried by John McCain or George Bush. They could get spooked and be even less willing to stick with the president's agenda.

Pollster Joel Benenson, who is a member of the president's political team, says that would be a mistake.

"Every race is unique. That's the caveat I would give to candidates in competitive districts is, 'Don't think that what happened in New Jersey has anything to do with your congressional district in Michigan. It doesn't,' " he says. "I think you have to be in touch with what kind of change people wanted economically when it comes to issues like health care, energy or reform. And I think that you could misread and misinterpret these results far too easily."

But Cook predicts that Obama's job keeping his own party united behind him will get a little bit harder now.

"If I were a Democratic member of Congress, I would either listen to my heart or my pollster, but not so much President Obama," he says.

And that's a thought that has to worry the White House the day after the off-year elections.